The present invention improves on theft prevention systems which prevent items from being stolen by securing those items to larger relatively immobile objects (referred to as anchors). For example, the theft of personal computers, typewriters, adding machines, telephones, and other equipment of similar size is a serious problem for many businesses. To solve this problem, various types of "tie-down" security systems have been developed.
One system involves bolting, welding, or otherwise rigidly attaching the item to be secured to an anchor like a desk, table, or wall. While making it difficult to steal the items, this system also prevents any movement or adjustment of the item by a user. For instance, if a typewriter is rigidly attached to a table it would be difficult for a typist to adjust the position of the typewriter to suit the typist's preference.
To allow some movement of the item and at the same time keep the item permanently attached to the anchor, systems using chains or cables have been used. These cable systems have a cable permanently attached at one end to the center of a solid plate, or permanently attached to one of the solid plate's outer edges. The plate is then affixed to the item to be secured, such as with a "double-sticky" adhesive pad. The other end of the cable is then attached to the anchor.
Attaching the cable to the edge of the plate presents a weakness in this type of system. This is because substantially all of the force exerted against the plate as the item is pulled or yanked away from the anchor is isolated along the edge of the plate to which the cable is attached. Only a small fraction of the adhesive pad holding the plate thus effectively opposes the removal force. The plate then acts as a lever, with the end furthest from the point where the cable is attached serving as a fulcrum. The result is that the plate can be peeled away from the item that it is supposed to secure, which obviously reduces the effectiveness of the security system.
The design in which the cable is attached to the center of the plate, although distributing a removal force more evenly over the area of the plate, nevertheless is subject to failure because the cable can be pulled free of the plate. That is, the cable end, which is attached to the plate by bolts, rivets, swedging and the like, can be yanked from the plate. The plate remains attached to the item to be secured, but the item is no longer connected to the anchor.
An additional disadvantage of this center-attached design is that there may not be enough clearance underneath the item to be secured (such as a typewriter or telephone) for the plate. This occurs because the cable and its attachment to the plate protrude from the surface of the plate. Thus, to avoid this problem, the plate would have to be attached to the back, side, or some other readily visible part of the secured item, which is unsightly and undesirable.